In accordance with development of information processing techniques, various recognition engines executing recognition processes have been developed. For example, there exist various recognition engines, such as a recognition engine that identifies a person from still image data, a recognition engine that generates location information tracing the flow of a person from moving image data, and a recognition engine that generates text data from speech data. As one example, Patent Document 1 discloses a robot that is equipped with recognizers for image recognition and speech recognition.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-283959
Although various recognition engines have been developed as described above, the respective recognition engines are incorporated in specific systems depending on individual applications, and therefore, it is difficult to use these recognition engines for other purposes. Even if it is intended to reuse the recognition engines, development of a new system capable of using the recognition engines needs huge cost because output formats of the recognition engines are different from each other. Thus, there is a problem that it is impossible to flexibly respond to an application's request for use of output results acquired from a plurality of recognition engines and development of such a system needs huge cost.